The present invention generally relates to a vehicle transmission and more particularly, to a method and an apparatus for determining the position of the shift rail portion of the vehicle transmission.
Transmissions are adapted to transfer or couple torque (i.e., energy) from one portion of a vehicle to another. Particularly, each of these transmissions include several selectively engagable gears which cooperatively provide a variety of selectable gear configurations or coupling arrangements which respectively couple or transfer the received torque in a unique manner (i.e., the conventionally referred to xe2x80x9cfirst gearxe2x80x9d arrangement couples or transfers the torque differently than does the conventionally referred to xe2x80x9cthird gearxe2x80x9d arrangement).
While a relatively wide variety of transmissions exist, each of these transmissions are typically of one of two general types which are respectively and often referred to as an xe2x80x9cautomaticxe2x80x9d and a xe2x80x9cmanualxe2x80x9d transmission arrangement. In the former arrangement, the gears are xe2x80x9cautomaticallyxe2x80x9d configured in the desired manner upon the single movement of a shift device. In the latter arrangement, the gear configuration must be xe2x80x9cmanuallyxe2x80x9d achieved by the movement of a shift rail member in a desired and relatively complicated manner. While a manual transmission increases the complexity of driving a vehicle, it does provides a better torque transfer efficiency than an automatic type of vehicle transmission.
Attempts have been made to simplify the required shifting of a manual transmission by the use of a selectively depressible switch which communicates with a controller. Particularly, the switch is adapted to selectively occupy several positions and to communicate a unique command signal to the controller upon occupying each of the respective positions. In operation, each switch position and the associated position command signal uniquely corresponds to a certain gear arrangement. In response to a command from the switch, the controller moves the shift rail member to cause the gear configuration which is specified or xe2x80x9ccommandedxe2x80x9d by the currently received signal to be achieved, thereby allowing for an efficient torque transfer while concomitantly simplifying the overall shifting process.
While these previously delineated attempts did provide the foregoing benefits, they suffered from some drawbacks. For example, these controllers did not have knowledge of the position of the shift rail (i.e., the gear arrangement of the transmission) prior to receipt of a position command signal. Rather, these controllers were adapted to receive the signal and to provide the desired gear configuration. Since certain gear configurations may not properly follow other configurations without increasing the likelihood of damaging the transmission, such a poverty of knowledge increased the likelihood of such undesired gear movement, thereby increasing the likelihood of damaging the transmission. Further, these controllers were not adapted to ensure that the shift rail was actually moved in the manner required by the received command signal, thereby preventing potential faults within the transmission assembly from being identified and further increasing the overall likelihood of transmission damage.
There is therefore a need for a method and an apparatus to detect the position of a shift rail in a manner which allows at least some of the foregoing drawbacks and disadvantages to be overcome.
It is a first object of the present invention to provide a method and an apparatus for detecting the position of a shift rail in a manner which overcomes at least some of the foregoing drawbacks and disadvantages.
It is a second object of the present invention to provide a method and an apparatus for detecting the position of a shift rail in a manner which allows for the efficient transfer of torque while concomitantly allowing for a relatively uncomplicated and efficient method for selecting a desired gear arrangement.
It is third object of the present invention to provide a vehicle transmission which allows gears to be relatively easily interconnected and which further allows the interconnection state of the gears to be identified and communicated in a manner which overcomes at least some of the previously delineated drawbacks and disadvantages to be overcome.
According to a first aspect of the present invention an assembly is provided which detects the rotation and the axial movement of a shift rail.
According to a second aspect of the present invention an apparatus for use in combination with a first selectively movable member is provided. The apparatus comprises a second member which is contacted by the first member when the first member moves in a first direction; a third member which is contacted by the first member when the first member moves in a second direction; and a signal generation assembly which senses the movement of the second and third members and which generates a first signal upon the movement of the second member and a second signal upon the movement of the third member.
According to a third aspect of the present invention a method is provided. The method includes the steps of providing gears; selectively engaging the provided gears in a desired manner; and generating a signal upon the selective engagement of the gears.
These and other features, aspects, and advantages of the present invention will become apparent from a reading of the following detailed description of the preferred embodiment of the invention and by reference to the following drawings.